<template>
  <div class="todo-footer">
    <label>
      <input type="checkbox" v-model="checkAll" />
    </label>
    <span>
      <span>已完成{{ complateNum }}</span> / 全部{{ todoList.length }}
    </span>
    <button class="btn btn-danger" @click="emit('clearComplate')">清除已完成任务</button>
  </div>
</template>

<script lang="ts">
import { computed, defineComponent } from 'vue'
import type { todoListType } from '../../App'
export default defineComponent({
  name: 'Footer'
})
</script>
<script lang="ts" setup>

const emit = defineEmits<{
  (event: "allChecked", checkType: boolean): void
  (event: "clearComplate"): void
}>()

const props = defineProps<{
  todoList: todoListType
}>()
//计算属性计算当前已经完成的数量
const complateNum = computed(() => {
  return props.todoList.reduce((p, c) => (
    c.done ? p + 1 : p
  ), 0)
})

//全选按钮的可读可写的计算属性
const checkAll = computed({
  get() {
    return complateNum.value === props.todoList.length
  },
  set(checkType) {
    emit("allChecked", checkType)
  }
})


</script>

<style lang="scss" scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>